Playing field obstacle



FIG. 1 is a front elevational view of my design for a playing field obstacle;

FIG. 2 is a rear elevational view of the playing field obstacle of FIG. 1;

FIG. 3 is a left elevational side view of the playing field obstacle of FIG. 1; and,

FIG. 4 is a right elevational side view of the playing field obstacle of FIG. 1.

The broken lines are included for the purpose of illustrating portions of the playing field obstacle that form no part of the claimed design. 

The ornamental design for a playing field obstacle, as shown and described. 